Table 1.

Cumulative data prior to pacing, after 2 wk of pacing, and after 2 wk without pacing

	Collective Data			P Values
	Baseline (n = 10)	125/min (n = 10)	Recovery (n = 8)	Baseline vs. 125/min	Baseline vs. Recovery
Body wt/heart rate
Body wt, kg	42 ± 3	44 ± 2	46 ± 2	0.01*	<0.01*
Heart rate, min−1	90 ± 5	125	81 ± 4	<0.01*	0.01*
Atrial pacing, %		75 ± 20
Gross anatomy
LV mass, g			118 ± 14
RV mass, g			35 ± 3
LV echocardiography
EDD, mm	31.9 ± 2.8	35.2 ± 2.8	32.9 ± 2.8	0.03*	0.37
ESD, mm	20.7 ± 3.8	25.6 ± 3.2	21.7 ± 2.6	<0.01*	0.26
A2-D, cm2	9.7 ± 1.7	11.0 ± 2.4	9.3 ± 1.9	0.08	0.95
A2-S, cm2	5.5 ± 1.6	7.6 ± 1.5	5.3 ± 1.6	0.01*	0.85
LV EDV, ml	25.4 ± 5.4	34.2 ± 11.1	24.2 ± 5.3	<0.01*	0.37
LV ESV, ml	10.5 ± 2.7	18.0 ± 9.2	10.8 ± 3.0	<0.01*	0.14
EF, %	58 ± 6	54 ± 4	55 ± 4	0.16	0.30
Mass-to-volume ratio, g/ml	3.4 ± 0.8	2.5 ± 0.8	3.6 ± 0.7	<0.01*	0.84
E/E′ lat	7.6 ± 2.0	7.0 ± 2.9	5.4 ± 1.7	0.56	0.07
Heart failure assessment
Tachypnea, %	0 (0)	0 (0)	0 (0)
Crackles, %	0 (0)	0 (0)	0 (0)
BNP, ng/ml	2.9 ± 2.5	3.4 ± 2.9	3.0 ± 2.7	0.09	0.19
NE, ng/ml	0.4 ± 0.5	0.4 ± 0.3	0.4 ± 0.3	0.84	0.80
Galectin-3, ng/ml	23 ± 8	23 ± 6	24 ± 8	0.98	0.49

Values are means ± SD. Baseline, prior to pacing; 125/min, after 2 wk of pacing; Recovery, after 2 wk without pacing; LV, left ventricle; RV, right ventricle; EDD, end-diastolic diameter; ESD, end-systolic diameter; A2-D, parasternal short-axis LV area at end diastole; A2-S, parasternal short-axis LV area at systole; EDV, end-diastolic volume; ESV, systolic volume; EF, ejection fraction; E/E′ lat, ratio of early ventricular filling peak velocity to lateral early diastolic mitral annular velocity; BNP, B-type natriuretic peptide; NE, norepinephrine.

^*Significant difference (P < 0.05).